Builder's Alert - KAT2: Tight Clearance between boards.
Sat, 26 Feb 2000

Summary: Move the two lock washers on ATU Control board from the bottom to the top of the ATU Control PCB.

Following several comments on the Elecraft reflector regarding a tight fit between the top and bottom boards of the KAT2 ATU, we re-measured all of the components. We have determined that the total stack up of component height tolerances for the BNC connectors on the Control PCB and the Relays on the LC PCB can add up to 0.8 MM more than the length of the 13/16" spacers (20.63 MM) that separate the two PC boards. This leaves a small gap between the spacers and the PC boards when the two boards are mated together.

While in most cases it is probably OK to let the PC boards pull together slightly as you tighten the screws, we now recommend that you move the two lock washers from the bottom of the ATU control board to the top side of the the control board, between the PC board and the spacers. This fills the gap nicely and creates a better fit.